合金化时间对热镀锌IF钢板镀层相结构的影响

Effect of galvanneal time on coating phase structure of IF galvanized sheet

通过模拟合金化镀锌试验,研究了IF钢合金化镀层结构随着合金化时间的演变规律。结果表明:在520℃合金化时,随着合金化时间的延长,镀层中铁含量快速增加,而当铁含量超过12%时,增长缓慢。合金化7 s时,镀层从表面到基板依次是纯锌η相、柱状ζ相(Fe Zn13)以及栅状δ1P相;随着时间增加,基体Fe继续向镀层扩散,纯锌η相、柱状ζ相消失,栅状δ1P相逐渐转变为致密的δ1k相,同时在基板处生产了齿状的Γ相,在合金化17 s后,镀层相结构最终稳定为δ1k相和基板处少量的Γ相。

Microstructure evolution rule of phase structure of coatings on IF galvanealed sheet with galvannealing time was studied by galvannealing simulation test.The results show that galvannealed at 520 ℃,Fe content in the coating increases rapidly with the galvannealing time prolonging,but grows slowly when it reaches 12%.At the beginning,galvannealed for 7 s,the zinc coating consists of a pure zinc,columnar ζ-Fe Zn13 particles and palisade-like δ1Player,then Fe in the steel substrate continues to diffuse to the coating with galvannealing time,the zinc layer and columnar ζ-Fe Zn13 particles disappear,the palisade-like δ1Player transform to the compact δ1klayer,and at the same time,the tooth-like Γ phase is produced adjacent to the steel substrate.The coating structure ultimately consists of δ1klayer and Γ phase when galvannealed for 17 s.